Segment Information - Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	$ 272,872	$ 230,797	$ 779,700	$ 679,380
Cost of service revenue	172,856	140,832	488,384	413,561
Provision for bad debts	3,194	3,275	8,238	11,658
General and administrative expenses	75,669	66,999	221,077	201,296
(Gain) Loss on disposal of assets	(177)	142	(23)	1,389
Operating income	21,330	19,549	62,024	51,476
Interest expense	(995)	(816)	(2,615)	(2,167)
Income before income taxes and noncontrolling interest	20,335	18,733	59,409	49,309
Income tax expense	7,445	6,562	20,410	15,500
Net income	12,890	12,171	38,999	33,809
Less net income (loss) attributable to noncontrolling interests	1,984	2,555	7,321	7,043
Net income attributable to LHC Group, Inc.’s common stockholders	10,906	9,616	31,678	26,766
Total assets	765,053	613,453	765,053	613,453	$ 614,071
Home health services
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	198,978	167,529	575,180	492,090
Cost of service revenue	123,204	100,057	352,896	294,359
Provision for bad debts	2,661	2,049	5,796	8,122
General and administrative expenses	55,980	50,293	165,153	150,948
(Gain) Loss on disposal of assets	20	20	39	811
Operating income	17,113	15,110	51,296	37,850
Interest expense	(746)	(612)	(1,961)	(1,640)
Income before income taxes and noncontrolling interest	16,367	14,498	49,335	36,210
Income tax expense	5,703	5,133	16,712	11,026
Net income	10,664	9,365	32,623	25,184
Less net income (loss) attributable to noncontrolling interests	1,759	1,853	6,053	5,002
Net income attributable to LHC Group, Inc.’s common stockholders	8,905	7,512	26,570	20,182
Total assets	515,562	425,923	515,562	425,923
Community-based services
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	12,146	11,793	33,807	32,823
Cost of service revenue	8,971	9,100	24,905	24,656
Provision for bad debts	30	190	404	488
General and administrative expenses	2,387	2,263	6,957	6,557
(Gain) Loss on disposal of assets	0	0	0	46
Operating income	758	240	1,541	1,076
Interest expense	(50)	(41)	(130)	(106)
Income before income taxes and noncontrolling interest	708	199	1,411	970
Income tax expense	338	83	602	413
Net income	370	116	809	557
Less net income (loss) attributable to noncontrolling interests	(21)	0	(7)	(57)
Net income attributable to LHC Group, Inc.’s common stockholders	391	116	816	614
Total assets	44,621	33,549	44,621	33,549
Hospice Services
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	41,291	35,322	116,249	100,051
Cost of service revenue	27,441	21,243	75,187	61,836
Provision for bad debts	234	797	1,393	2,364
General and administrative expenses	11,263	9,491	32,404	27,787
(Gain) Loss on disposal of assets	13	5	21	329
Operating income	2,340	3,786	7,244	7,735
Interest expense	(149)	(90)	(393)	(232)
Income before income taxes and noncontrolling interest	2,191	3,696	6,851	7,503
Income tax expense	931	1,275	2,439	2,484
Net income	1,260	2,421	4,412	5,019
Less net income (loss) attributable to noncontrolling interests	273	553	1,038	1,368
Net income attributable to LHC Group, Inc.’s common stockholders	987	1,868	3,374	3,651
Total assets	156,296	119,906	156,296	119,906
Facility-based services
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	20,457	16,153	54,464	54,416
Cost of service revenue	13,240	10,432	35,396	32,710
Provision for bad debts	269	239	645	684
General and administrative expenses	6,039	4,952	16,563	16,004
(Gain) Loss on disposal of assets	(210)	117	(83)	203
Operating income	1,119	413	1,943	4,815
Interest expense	(50)	(73)	(131)	(189)
Income before income taxes and noncontrolling interest	1,069	340	1,812	4,626
Income tax expense	473	71	657	1,577
Net income	596	269	1,155	3,049
Less net income (loss) attributable to noncontrolling interests	(27)	149	237	730
Net income attributable to LHC Group, Inc.’s common stockholders	623	120	918	2,319
Total assets	$ 48,574	$ 34,075	$ 48,574	$ 34,075